Pulp refiner



H. G. WELSFORD x-:T Al., 1,961,808

PULP REFINER Filed March 2, 1953 3 Sheets-Sheet 1 June 5, 1934.

INVENTORS HuBEm-.GMIEISFORD ANDREunRussEu.

Y Z M17@ ATTORNEY June 5, 1934- H. G. WELSFORD Er AL 1,951,808

PULP REFINER Filed March 2, 1933 3 Sheets-Sheet 2 I N VE NT 0R S HUBERT. G YIELSFORD ANDREW-H -RUSSELL AT TORNEY June 5, 1934. H, G,WELSFORD Er AL 1,961,808

PULP REFINER :u I i l@ iIl *Q hl 'i f5 (2W I Xx Il E: i u IIll i i Y. lI" Si? V -TINVENMS :o n. numexmsmnn E :n Rami-Russen,

AT TORNEY Patented June 5, 1934n UNITED sTATEs PATENT PULP REFINEB,

Hubert G. Welsf'ord and Andrew N. Russell,

Montreal, Quebec,

Canada, usignors to Dominion Engineering Works Limited, Lachine,

Quebec, Canada Application March 2, 1933,` Serial No. 659,373

6 Claims.

This invention relates to improvements in frusto-conical pulp refinersof the Wiener type described in U. S. Patent No. 1,730,908, datedOctober 8, 1929.

The principal purpose of this invention is to increase the effectivenessof the Wiener rener with respect to treatment of pulp containing knots,coarse partially uncooked wood chips, or other coarse constituents sothat plugging or clogging of the refiner, with its consequentinterruption of the refining operation, as ordinarily caused by thepresence of these constituents, is avoided.

Another purpose is to provide an improved rener of the Wiener type thatis also useful in connection with the preliminary reduction of coarsefibrous materials such as the rejects from wood pulp screens as onestage in the refining of such materials for the manufacture of pulp andpaper products.

The main features of improvement by which the foregoing objects areattained resides in the provision of a special breaking or reducing zonein which the knots and other coarse constituents of the pulp or flbrousmaterial are broken down or reduced to suitable proportions and thenforced into the refining zone between the shell and plug of the rener.This breaking or reducing zone comprises a breaking chamber formed by acylindrical wall extension of the refiner shell and one or more breakeror hammer members co-operating with the inner wall surface of saidchamber to effect the breaking down or reduction of the coarseconstituents of the pulp or fibrous material. The inner wall surface ofthe breaking chamber is preferably corrugated to provide spirallyextending ridges and valleys which are substantially V-shaped in crosssection and the co-operating breaker or hammer members are eitherrigidly or pivotally fastened to the rotating plug or shaft of therenner so that the operating clearance between these members and theridges of the surrounding wall surface is so small that/ it ispractically impossible for any particles of the coarse material tobecome wedged therebetween. After the material has been reduced by theviolent impacts and tearing action to which it is subjected between thecorrugated wall of the breaking chamber and the co-operating breaker orhammer members, it is positively forced, by the spiral formation of saidcorrugated surface, into the reducing zone between the opposing surfacesof the plug and the main portion of the shell.

In the Weiner refiner there is an impeller carried by the rotating plugand operating in a cylindrical wall extension of the reflner shell butthe design and diameter of this impeller is such that it servesprincipally to apply the pressure necessary-to force the materialthrough the refining zone and has only a limited breaking action whichis insufcient to enable pulp or other flbrous material containing coarsechips, knots and other coarse constituents to be treated continuouslywithout danger of plugging the reflner to the point where stoppage andclearing of the refiner becomes necessary. In the Wiener reflner theinner surface of the shell, including the cylindrical extensionenclosing the impeller, is provided with alternating grooves and barswhich are approximately square in cross section and we have discoveredthat this shaping of the grooves and bars, together with the smalldiameter of the impeller, are factors that contribute to the pluggingwhich ensues when the pulp being rened contains the very coarseconstituents previously referred to. In the present invention thisdiiliculty is largely avoided by making the ridges and valleys of thebreaking chamber substantially V or saw tooth shape in cross section andby the reservation of minimum clearance between the said ridges and thebreaker or hammer members.

Proceeding now to a more detailed discussion of the present invention,reference will be had to the following drawingsz Fig. 1 is a view,partly in side elevation and partly in longitudinal section, of a Wienerrenner assembly modified in accordance with the present invention.

Fig. 2 is an elevation of the breaker members provided in accordancewith this invention.

Fig. 3 is a sectional view along the line 3-3 of Fig. 2.

Fig. 4 is van elevation of a casing ring which forms part of thebreaking chamber provided in accordance with this invention.

Fig. 5 is a sectional view along the line 5-5 'of Fig. 4.

Fig. 6 is a fragmentary, vertical sectional view of a portion of therefiner, showing a modification of the present invention.

Fig. 7 is a transverse sectional view along, the line 7-7 of Fig. 6.

In Figs. 1 to 5 inclusive, 11 designates a frustoconical shell and 12 arotary frusto-conical plug operating therein, the opposing surfaces ofthe shell and plug being provided with the usual lengthwise extendinggrooves 13 and bars or knives 14. According to the present invention abreaking chamber 15 is provided between the inlet casting 16 and theadjacent large or inlet end of the shell 11. Said chamber is preferablyformed by two casing rings 17 which are fastened in place between theinlet casting and the shell by bolts, studs or other fastening means(not shown) and have their perpendicular surfaces stepped to provide thespigot joints appearing at 18. The inner surfaces of the casing rings 17are shaped (as shown in Figs. 4 and 5) to present alternating spiralridges and valleys which are substantially saw toothed or V-shaped incross section, the ridges being indicated at 19 and the valleys at 20.The direction of inclination of these ridges and valleys is such thatmaterial which is crushed or reduced in the valleys by the breakermembers hereinafter mentioned is positively forced from the breakingchamber 15 into the communicating refining zone afforded Abetween theopposing surfaces of the plug and shell elements.

The small end of the shell 11 is attached in the usual manner to theoutlet casting 21 which, together with the inlet casting 16, is mountedon the base 22. These castings 16 and 21 are provided with openings 23and packing glands 24 for the passage of a shaft 25 to which the plug 13is keyed as indicated at 26. Shaft 25 is journalled in longitudinallyadjustable bearings 27 which are carried by pedestals 28 rising from thebase 22. The bearing 27 supporting the right hand end of the shaft isconnected with the usual adjusting means-29 (Fig. 1) through the agencyof which the plug 13 is moved axially to vary the clearance between theopposing surfaces of the plug and shell. The opposite end of shaft 25 iscoupled as at 30 with the shaft of an operating motor 31, also mountedon the base 22.

The breaker members provided in accordance with this invention operatein the breaking chamber l5 and are indicated at 33. These members aredisposed radially with respect to the shaft 25 and are cast integralwith or otherwise rigidly secured to the outer surface of a base ring34. Said base ring 34 is fitted in a recess 35 formed in the large endof the plug 12 a'nd is anchored in place by bolts or studs 36. The basering 34 is also preferably keyed to the shaft 25 through the agency ofthe keyway appearing at 37, said keyway receiving therethrough a portionof one of the keys 26 by means of which the plug l2 is keyed in place onthe shaft.

As shown in Figs. 2 and 3 the tips of the breaker members 33 areprovided with notches 38 which are preferably made V shaped so thatthese notches will be self clearing as regards accumulation of crushedmaterial therein. The breaker members are mounted and proportioned sothat only a relatively small clearance is reserved between the tips ofthese members and the opposing ridges 19 of the breaking chamber. Theadvantage of this small clearance is that it prevents knots, chips andother coarse particles, which enter the breaking chamber through theinlet casting 16, becoming wedged between the breaker members and thesurrounding casing ring 17.

In operation the material to be treated is delivered from the inletcasting 1-6 into the breaking c-hamber l5 where the knots, coarsepartially uncooked wood chips and other coarse constituents areviolently impacted and torn between the tips of the breaker members 33and the ridges 19 of the surrounding casing ring 17. As theseconstituents become sufficiently reduced they are positively forced, byreason of the inclination of the ridges 19, into the refining zonebetween the opposing surfaces of the plug and shell from which therefined material is ultimately delivered to the outlet casting 21.

It is essential that the breaker members 33 rotate relative to thesurrounding Wall of the breaking chamber but itis not essential thatthese breaker members be directly attached to the plug as describedherein. They may, for example, be attached in any' suitable.mannerdirectly to the rotary shaft 25 so that they travel with but not as apart of the plug 12. It is also not essential that the breaker membersbe rigidly secured in their radial positions with respect to the shaft25' since satisfactory results are obtained when Athe breaker membersare mounted to have a slight swinging movement permitting them to act inthe manner of hammers as they are carried around the interior of thebreaking chamber. One example of the latter construction is shown inFigs. 6 and 7 wherein the breaker members 33a are pivotally secured tothe plug 12a by means of the trunnions 34a. In this case the large endof the plug 12a is provided with axially extending bores 12b fitted withbushing 12c in which the trunnions 34a are rotatably mounted. Set screws39 are threaded through radial openings of the plug so that the innerends of these screws engage in annular grooves 34h formed in thetrunnions 34a.a'nd serve to hold the latter against axial displacement.The heads of the set screws are seated in recesses formed in the bottomwalls of certain of the grooves 13 of the plug as clearly shown in Fig.6.

Having thus described our invention, what we claim is:-

1. A reiiner comprising a frusto-conical shell, a rotary frusto-conicalplug operating therein, said shell having a cylindrical extension at itsinlet end projecting beyond the corresponding end of the plug andpresenting a serrated inner surface and a plurality of breaker membersmounted to revolve with said plug, the tips of said members beingopposed to the serrated surface of the shell extension and being spaceda minimum distance therefrom so that coarse fibrous constituentssupplied to said reiiner are subjected to a preliminary refiningtreatment between the serrated surface of the shell extension and thebreaker members and then forced into the main refining zone afforded bythe opposing refining surfaces of the plug and shell.

2. A refiner as claimed in claim l in which the serrations at the innersurface of the shell extension present relatively sharp edges opposingthe tips of the breaker members and are spirally inclined with respectto the longitudinal axis of the shell.

3. A refiner as claimed in claim 1 in which the tips of the breakermembers are provided with one or more V-shaped notches.

4. A rener as claimed in claim 1 in which the tips of the breakermembers are serrated.

5. A pulp reiiner of the frusto-conical plug and shell type including abreaking chamber formed as a continuation of the inlet end of saidshell, the inner wall surface of said chamber being formed to presentalternating spiral ridges and valleys of triangular cross-section and aplurality of breaker members mounted in said chamber so as to travelwith said plug, said breaker members being so yproportioned and-

